연령이 다른 Bald/Caj 생쥐의 피부창상치유중 섬유모세포의 동원

유영현,김동환,고재승,한성수,한성수,한성수 대한해부학회 1994 Anatomy & Cell Biology Vol.27 No.4

Preparation of porous cordierite ceramic with acid-leached coal gangue

Wang Xu-Dong,Xu Hai-Yan,Zhang Feng-Jun,Li Dong-Cai,Wang Ai-Guo,Sun Dao-Sheng,오원춘 한국세라믹학회 2020 한국세라믹학회지 Vol.57 No.4

The eff ect of impurities in coal gangue on the sintering and properties (porosity and compressive strength) of porous cordierite ceramics has been investigated by adjusting the amount of impurities by controlling the acid–gangue ratio during acid leaching. The sintering behavior and microstructure of the porous ceramics have been characterized via X-ray diff ractometry and scanning electron microscopy. The eff ects of both the acid–gangue ratio and sintering temperature on the porosity and compressive strength have been also investigated. The results indicated that both porosity and compressive strength of the porous cordierite ceramics prepared using acid-leached coal gangue were evidently improved. The content of the impurities in coal gangue was adjusted via acid leaching by controlling the acid–gangue ratio. The appropriate content of impurities in coal gangue facilitated the sintering process and improved the porosity and compressive strength of the obtained porous cordierite ceramics.

Characterization and Electrical Conductivity of Carbon-Coated Metallic (Ni, Cu, Sn) Nanocapsules

Wang, Dong Xing,Shah, Asif,Zhou, Lei,Zhang, Xue Feng,Liu, Chun Jing,Huang, Hao,Dong, Xing Long Korean Society of Microscopy 2015 Applied microscopy Vol.45 No.4

Carbon-coated Ni, Cu and Sn nanocapsules were investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM) and a four-point probe device. All of these nanocapsules were prepared by an arc-discharge method, in which the bulk metals were evaporated under methane ($CH_4$) atmosphere. Three pure metals (Ni, Cu, Sn) were typically diverse in formation of the carbon encapsulated nanoparticles and their different mechanisms were investigated. It was indicated that a thick carbon layers formed on the surface of Ni(C) nanocapsules, whereas a thin shell of carbon with 1~2 layers covered on Cu(C) nanocapsules, and the Sn(C) nanocapsules was, in fact, a longger multi-walled carbon nanotubes partially-filled with metal Sn. As one typical magnetic/dielectric nanocomposite particles, Ni(C) nanocapsules and its counterpart of oxide-coated Ni(O) nanocapsules were compared in the electrically conductive behaviors for further applications as the electromagnetic materials.

Tracking Control of Podded Propulsion Unmanned Surface Vehicle with Unknown Dynamics and Disturbance Under Input Saturation

Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4

This paper addresses two interrelated problems concerning the tracking control of podded propulsion unmanned surface vehicle (USV), namely, the modeling of podded propulsion USV, and trajectory tracking controller design. Based on the force analysis, the separation model of podded propulsion USV is established. Furthermore, a practical adaptive neural tracking controller is proposed by backstepping technique, neural network minimum parameter learning method, neural shunting model and auxiliary dynamic system without the exact information of hydrodynamic damping structure and the sea disturbances. Using Lyapunov stability analysis theory, it is proven that all error signals in the system are uniformly ultimately bounded. The advantages of the paper are that first, the underactuated characteristic of podded propulsion USV is demonstrated; then, neural shunting model and neural network minimum parameter learning method are introduced to cope with the problem of "explosion of complexity" and uncertainty factors, respectively; third, auxiliary dynamic system is introduced into controller design to reduce the risk of actuator saturation. Taking into account the above practical problems is helpful to engineering implementation in the marine practice. Finally, numerical simulation has been given to demonstrate the effectiveness of the proposed scheme.

Formation Control Strategy for Underactuated Unmanned Surface Vehicles Subject to Unknown Dynamics and External Disturbances with Input Saturation

Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.11

This paper addresses the formation tracking control problem of multiple underactuated unmanned surface vehicles. Considering many actual situations, a practical formation control scheme, which is performed by using a leader-follower approach, minimum learning parameter technique, adaptive technology and so on. Firstly, a virtual unmanned surface vehicle is designed according to the location information of the leader unmanned surface vehicle to estimate the leader’s speed information while reducing the communication bandwidth. Secondly, a formationcontrol law is designed to make the follower underactuated unmanned surface vehicles track the leader. Unknown dynamics and external disturbances are regarded as a whole and compensated by the minimum learning parameter technique instead of multi-layer neural network and the neural shunt model can handle multiple derivation problems of virtual control laws. Meanwhile, the robustness of the controlled system is improved through adaptive technology. Besides, an auxiliary design system is employed to constrain the output range of the control law. Finally, numerical simulations are implemented to prove the feasibility of the formation tracking control strategy.

당뇨병 치료에 유용한 녹차 약리활성성분의 분석과 복합추출에 관한 연구

Wang Dong Feng,Xie Xiao Feng,Yan Jun,Wang Zenong 한국식품과학회 1997 국제녹차심포지엄 Vol.1997 No.1

A Novel Ginsenosidase from an Aspergillus Strain Hydrolyzing 6-O-Multi- Glycosides of Protopanaxatriol-Type Ginsenosides, Named Ginsenosidase Type IV

( Dong Ming Wang ),( Hong Shan Yu ),( Jian Guo Song ),( Yu Feng Xu ),( Chun Ying Liu ),( Feng Xie Jin ) 한국미생물 · 생명공학회 2011 Journal of microbiology and biotechnology Vol.21 No.10

Herein, a novel ginsenosidase, named ginsenosidase type IV, hydrolyzing 6-O-multi-glycosides of protopanaxatrioltype ginsenosides (PPT), such as Re, R1, Rf, and Rg2, was isolated from the Aspergillus sp. 39g strain, purified, and characterized. Ginsenosidase type IV was able to hydrolyze the 6-O-α-L-(1→2)-rhamnoside of Re and the 6-O-β-D- (1→2)-xyloside of R1 into ginsenoside Rg1. Subsequently, it could hydrolyze the 6-O-β-D-glucoside of Rg1 into F1. Similarly, it was able to hydrolyze the 6-O-α-L-(1→2)- rhamnoside of Rg2 and the 6-O-β-D-(1→2)-glucoside of Rf into Rh1, and then further hydrolyze Rh1 into its aglycone. However, ginsenosidase type IV could not hydrolyze the 3-O- or 20-O-glycosides of protopanaxadioltype ginsenosides (PPD), such as Rb1, Rb2, Rb3, Rc, and Rd. These exhibited properties are significantly different from those of glycosidases described in Enzyme Nomenclature by the NC-IUBMB. The optimal temperature and pH for ginsenosidase type IV were 40℃ and 6.0, respectively. The activity of ginsenosidase type IV was slightly improved by the Mg2+ ion, and inhibited by Cu2+ and Fe2+ ions. The molecular mass of the enzyme, based on SDS-PAGE, was noted as being approximately 56 kDa.

A Time-Varying Lookahead Distance of ILOS Path Following for Unmanned Surface Vehicle

Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.5

This paper is concerned with the path following control for an unmanned surface vessel subject to unknown dynamics and external disturbance. Firstly, an integral Line-of-Sight navigation strategy based on a fuzzy strategy to optimize lookahead distance to achieve faster convergence speed is proposed. Then a novel adaptive course control law based on trajectory linearization control technology is proposed, which is combined with the integral Line-of-Sight navigation strategy to form a complete unmanned surface vessel path following strategy. From the author’s point of view, this is the fi rst time that trajectory linearization control technology has been applied to the path following scheme by controlling the course. At the same time, in order to improve the robustness of the path following system, the unknown dynamics, external disturbance, and error in the system are compensated by neural network minimum learning parameter method with less computational complexity and a robust term, respectively. Furthermore, hyperbolic tangent function, Nussbaum function, and neural shunting model are introduced into the design of control law to solve the potential input saturation problem. Finally, the numerical simulation experiments of straight line and curve path following are given to prove the feasibility and universality of the whole set of path following scheme.

Design of Adaptive Neural Tracking Controller for Pod Propulsion Unmanned Vessel Subject to Unknown Dynamics

Dong-Dong Mu,Guo-Feng Wang,Yun-Sheng Fan 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.6

This paper addresses two interrelated problems concerning the tracking control of pod propulsion unmanned surface vessel (USV), namely, the modeling of pod propulsion USV, and tracking controller design. First, based on MMG modeling theory, the model of pod propulsion USV is derived. Furthermore, a practical adaptive neural tracking controller is proposed by backstepping technique, neural network approximation and adaptive method. Meanwhile, unlike some existing tracking methods for surface vessel whose control algorithms suffer from “explosion of complexity”, a novel neural shunting model is introduced to solve the problem. Using a Lyapunov functional, it is proven that all error signals in the system are uniformly ultimately bounded. The advantages of the paper are that first, the underactuated characteristic of pod propulsion USV is proved; second, the neural shunting model is used to solve the problem of “explosion of complexity”, and this is a combination of knowledge in the field of biology and engineering; third, the developed controller is able to capture the uncertainties without the exact information of hydrodynamic damping structure and the sea disturbances. Numerical examples have been given to illustrate the performance and effectiveness of the proposed scheme.

Design of Adaptive Neural Tracking Controller for Pod Propulsion Unmanned Vessel Subject to Unknown Dynamics

Mu, Dong-Dong,Wang, Guo-Feng,Fan, Yun-Sheng The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.6

This paper addresses two interrelated problems concerning the tracking control of pod propulsion unmanned surface vessel (USV), namely, the modeling of pod propulsion USV, and tracking controller design. First, based on MMG modeling theory, the model of pod propulsion USV is derived. Furthermore, a practical adaptive neural tracking controller is proposed by backstepping technique, neural network approximation and adaptive method. Meanwhile, unlike some existing tracking methods for surface vessel whose control algorithms suffer from "explosion of complexity", a novel neural shunting model is introduced to solve the problem. Using a Lyapunov functional, it is proven that all error signals in the system are uniformly ultimately bounded. The advantages of the paper are that first, the underactuated characteristic of pod propulsion USV is proved; second, the neural shunting model is used to solve the problem of "explosion of complexity", and this is a combination of knowledge in the field of biology and engineering; third, the developed controller is able to capture the uncertainties without the exact information of hydrodynamic damping structure and the sea disturbances. Numerical examples have been given to illustrate the performance and effectiveness of the proposed scheme.